The work aimed to evaluate the effect of irrigation with magnetically treated water on development, growth, and yield of the scarlet eggplant (Solanum gilo Raddi) cv. Morro Grande, in two growing seasons (autumn and spring). A completely randomized design in a 3x2 factorial scheme with three replications for the first growing season and 2x2 with five replications for the second growing season was used. Each experimental unit consisted of four plants spaced 0.75 m between plants and 1.00 m between rows. Factors consisted of irrigation using magnetically treated water, untreated water, three replacement of the crop evapotranspiration (50%, 75%, and 100% ETc) for the first growing season and two replacement of the crop evapotranspiration (75% and 100% ETc) for the second growing season. Stem diameter (millimeters), plant height (centimeters), shoot dry matter (grams), first flower and fruit (accumulated degree-days), number of fruits, fruit yield per plant (grams), and average fruit mass (grams) were evaluated. The water with magnetic treatment provided better results for the development variables, first flower, and first fruit in the second growing season. However, for the variables, stem diameter, plant height, shoot dry matter, fruit yield, and number of fruits, only the replacement irrigation depth factor obtained higher values for the 100% ETc than water-deficit treatments.